The invention relates to a novel side shield or door for use with an aluminum reduction cell or potline. In the production of aluminum, a reduction cell, a series of which is called a potline, is used made of heavy steel plate in the form of a shallow box supported on an insulated floor. The cell is lined with carbon, and steel bars are embedded in the bottom carbon lining to conduct current into a layer of molten aluminum which acts as the cathode. The anode is made of carbon and is hung from above with a lower end extending into a molten bath containing cryolite a charge of alumina and calcium fluoride floating on the molten aluminum layer. With passage of direct current, the alumina decomposes and aluminum deposits on the cathode, oxygen on the carbon anode, and the anode is gradually consumed. During operation of the cell, the alumina is also gradually consumed and when it drops to certain levels a warning light comes on to alert the operator that more alumina is needed. Also during the operation of the cell, various gases are formed at the anode such as carbon dioxide and carbon monoxide. Also present in the cell is a metal fog of finely divided metallic sodium or aluminum.
Accordingly, it is necessary at various times for operators to work in the direct area of the aluminum reduction cell. Normally, the upper part of the potline is covered and has a curved metallic side structure. Removable shields or doors are disposed over rectangular openings in the sides of the potlines. Removal of the shield enables the operators to add alumina when necessary, to check the operation and any malfunctions of the cells, and to observe the consumption of the anode and its disposition in the molten layer. Conventional shields or doors, presently used, are constructed of metal sheets or plates which eventually warp due to the heat involved in the cells. The warped shields do not adequately cover the openings in the cells and the noxious gases escape to the atmosphere in the area of the cells, thus presenting hazards to operators.